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RHEL 7 – Pacemaker – Configure Redundant Corosync Links on Fly– Part 10

Corosync Links - RHEL7

Corosync cluster engine provides the reliable inter-cluster communications between the cluster nodes. It syncs the cluster configuration across the cluster nodes all the time. It also maintains the cluster membership and notifies when quorum is achieved or lost. It provides the messaging layer inside the cluster to manage the system and resource availability. In Veritas cluster , this functionality has been provided by LLT + …

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RHEL 7 – Pacemaker – Define the Resource Behaviour – Part 9

Pacemaker resource agents

In Pacemaker/Corosync cluster, there are may aspects/key elements that we need to understand before playing with cluster operations. Otherwise , it might cause unnecessary outage/downtime for the services. The most important elements are setting the preferred resource location , ordering (defining dependencies) , resource fail counts, resource-stickiness, colocation, clone, master/slave, promote/demote etc. Let’s go through the article and understand how these elements contributes …

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RHEL 7 – Pacemaker – Cluster Node Management – Part 8

Redhat Cluster with Pacemaker

This article will demonstrates about the Pacemaker/Corosync cluster membership, node management and other  cluster operational tasks. Periodically , you might need to take the cluster node offline to perform the maintenance activities like OS package update/upgrade , hardware replacement/upgrade etc. In  such cases ,you need to put the cluster node in to standby mode to keep the cluster operational on other node …

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RHEL 7 – Pacemaker – Cluster Resources/Group Management – Part 6

RHEL 7 cluster Resource group

In Pacemaker/Corosync  cluster (RHEL 7 HA),  resources management and resource group management are important tasks . Depends on the cluster HA services, you might need to configure N-number of resources. In most of the cases , you might need to start set of resources sequentially, and stop in the reverse order.  To simplify this configuration, Pacemaker supports the concept of groups (Resource …

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RHEL 7 – Pacemaker – Cluster Resource Agents Overview – Part 5

Pacemaker resource agents

Resource agents plays an important role in cluster management.  Resource agents are multi-threaded processes that provides the logic to manage  the resources. Pacemaker has one agent per resource type. Resource type could be a File-system , IP address , databases, virtual-domain and more. Resource agent is responsible to monitor, start , stop,validate , migrate , promote and demote  the cluster resources whenever required. …

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RHEL 7 – Configuring Pacemaker/Corosync – Redhat Cluster – Part 4

Redhat cluster - pacemaker corosync configuration

In this article, we will see that how to configure two node Redhat cluster using pacemaker & corosync on REHL 7.2. Once you have installed the necessary packages, you need to enable the cluster services at the system start-up. You must start the necessary cluster services before kicking off the cluster configuration. “hacluster” user will be created automatically during the package …

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RHEL 7 – Installing Redhat Cluster Software (Corosync/pacemaker) – Part 3

Redhat Cluster 7 - RHEL 7 - Pacemaker installation

In this article, we will see that how to install Redhat cluster software (Pacemaker) on RHEL 7. If you have valid redhat subscription , you can directly configure redhat repository and install the packages. It also available in the RHEL 7 ISO image as an Add-on Package. Unlike previous redhat cluster releases , Redhat cluster 7 installation looks very simple since redhat has …

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RHEL 7 – Redhat Cluster with Pacemaker – Overview – Part 2

Redhat Cluster with Pacemaker

Pacemaker is robust and powerful opensource resource manager  which is shipping with  Redhat Enterprise Linux 7 as High Availability Add-on . Pacemaker simplified the cluster configuration and cluster management on RHEL 7 which is really good for system administrators. Compare to the prior redhat cluster release, Redhat cluster 7 looks completely different with corosync cluster engine and pacemaker resource manager. In this …

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